Research on the influence of a new tap drill geometry on C45, 42CrMo4 and X5CrNi8 steel processing

Abstract

The shearing of the chips in a blind hole thread presents a particular problem in machining industry. The tap geometry plays an important role in the tool's durability, influencing the forces during the tapping process and also the way in which the chips are evacuated. This paper analyzes the influence of the tap geometry on the cutting of materials such as C45, 42CrMo4 and X5CrNi8. An adequate geometry will extend the tap durability by controlling the chip when the tap reverses while still engaged in the tapping process. It relates to the improvement of a spiral tap drill, which discharges chips towards the shank via a helical flute. The article contains details about the tap geometries and the results obtained in this research. Based on the results obtained in this research, the purpose of this paper was achieved. The tap durability was improved, the chip deposition on the rake surface was reduced and the torsion torque has a smaller value compared to the standard tap geometry.